CATHETER DEVICE CONTAINING A SEPARATOR FOR RETAINING MAGNETIC PARTICLES IN A FLUID

Description

[0001] The invention lies in the field of mechanical engineering, mechanics, and fluid technology and is particularly advantageously applicable, for example, in medical technology. Specifically, the invention concerns the separation of magnetic particles from a fluid, in particular a liquid.

[0002] When transporting fluids through flow channels, it is generally undesirable for particles that are created, for example, through abrasion or otherwise enter the fluid circuit to be transported with the moving fluid. Typically, the transported particles are of no use and merely pose risks, for example by getting caught in moving parts such as ball bearings, plain bearings, motors or rotors, where they at least cause further abrasion or slow down or hinder movement through increased friction. This is all the more important when the volumes of fluid being moved are small and the speed of movement of the fluid is slow, such as in the circulation of irrigation fluid in catheters, where typically only milliliters are moved per minute. Furthermore, the moving parts used in medical catheters are usually very sensitive if unwanted particles get caught in them.

[0003] In some cases, unwanted particles can be filtered out of the fluid flow by mechanical filters, such as fabrics, but this is generally accompanied by an increase in flow resistance.

[0004] Particularly in catheters that use a rapidly rotating shaft to drive functional elements, such as blood pumps or angiography machines, wear of the shaft material has negative effects over time. Such shafts often consist of twisted strands, and increased wear occurs, particularly when the shaft is curved and the rotation speed is high, due to the flexion of the twisted strands against each other.

[0005] Magnetic filters are already known for the retention of magnetic particles. However, these are usually too large for low flow rates of a few milliliters per hour and are also unsuitable for use with saline solutions or other aggressive fluids. Membrane filters typically have too high a conduction resistance and are too large and expensive to be used as disposable filters, for example. Furthermore, membrane filters, and especially the amount of particles that accumulate in them, can significantly disrupt the function of a flexible shaft, for example, which can even lead to its destruction.

[0006] EP 2 246 078 A1 shows a shaft arrangement with a shaft that extends within a fluid-filled cavity and can be driven by a drive from outside the cavity. The shaft has a surface structure on its outer surface that, upon rotation, conveys the fluid in a flow direction in the longitudinal direction of the shaft. Provision is made here for a sleeve that is rotatable with the shaft and has at least one conveying element for conveying the fluid in a counterflow direction opposite to the flow direction. The aspect of mechanical wear of a shaft is not focused on here.

[0007] Against the background of the prior art, the object of the present patent is to create a protective device or a catheter device or a catheter system or a separating device which allows magnetic particles to be retained from a fluid flow without hindering or slowing down the fluid flow, wherein the separating device is also to be designed to withstand aggressive fluids.

[0008] The problem is solved with the features according to the independent patent claims.

[0009] The present patent relates, for example, to a catheter device comprising a catheter in which a rotating shaft consisting at least partially of a magnetic material is arranged, and comprising a separating device which comprises an annular body surrounding the rotating shaft and having a cavity containing a magnetic body, the magnetic body being arranged downstream of a point at which the shaft emerges from the catheter surrounding it, with respect to the direction of flow of the fluid through the catheter.

[0010] This clearly demonstrates that the separation device, combined with a corresponding catheter device, is particularly suitable for applications where the wear from a rotating shaft within a fluid flow needs to be separated. For example, in medical facilities, such catheters with rapidly rotating shafts are used to drive functional elements such as milling cutters for blood vessels or heart pumps. The resulting wear from the shaft material is harmful to the very fine and precise, yet sensitive, functional elements, such as the corresponding plain bearings. Therefore, it is particularly important in this context to absorb the wear from the shaft, which is typically made of stranded iron alloy wires.

[0011] It should be emphasized that all separating devices shown in this patent, whether according to the embodiments of the patent claims or according to the examples from the figures, can all serve in themselves as separating devices in a catheter device according to the invention.

[0012] In addition, part of a corresponding catheter device under this protective right can also be a catheter device with at least one valve for

[0013] Control of the fluid flow through the catheter, wherein the valve comprises: a valve control chamber into which an inflow channel with an inflow opening and an outflow channel with an outflow opening open, and a closure element which is movable in a controlled manner in the valve control chamber and which closes the outflow opening in at least a first position, the inflow opening in at least a second position and which keeps a connecting channel between the inflow opening and the outflow opening open in at least a third position, wherein a valve drive is provided which selectively moves the closure element at least into the first, second or third position.

[0014] Using a suitable control system or this valve, it is possible to direct the fluid flow through the transport channel in the desired direction. For example, fluid velocities or differential velocities through the transport channel can be specified, even reversing the fluid's direction. This is useful, for example, during flushing processes.

[0015] Examples of such valve control and fluid guidance are explained, for example, in the parallel application WO 2016 / 116608 filed by ECP GmbH on the same day. Furthermore, priority is claimed from the two prior applications EP 3 047 873 A1 and EP 3 047 911 A1.

[0016] A further development provides for the transport channel to have a cavity and / or a reservoir for the temporary storage of particles. This is advantageous because the accumulation of particles does not reduce the cross-section of the transport channel. The cavity and / or reservoir are designed in such a way that the magnet influences the binding of particles in such a way that the corresponding particles remain in the cavity or reservoir.

[0017] A further development provides for the cavity and / or the reservoir to have two ends, both of which are fluidically connected to the transport channel. For example, the cavity and / or the reservoir have a U-shape in which particles can collect ("diversion channel"). Alternatively, it is also possible for the cavity and / or the reservoir to have only one branch to the transport channel, for example, corresponding to a "siding." These two aforementioned variants have the characteristic that the flow through the transport channel is not disrupted and, above all, that additional storage volume is provided for abrasion debris. In particular, the flow in the transport channel should also prevent abrasion debris stored in the reservoir and / or the cavity from being torn off and fed back into the fluid flow through the transport channel.

[0018] A further advantageous development provides that the reservoir and / or the cavity are designed as a spatially limited (i.e. limited to a certain flow length) cross-sectional enlargement of the transport channel.

[0019] Also disclosed is a protective device for a functional element that can be combined with the claimed catheter device. Such a functional element can, in particular, be a seal or a bearing (in particular a ball bearing, a plain bearing, a needle bearing, or the like). Furthermore, a particularly sensitive part of the human or animal body from which abrasion is to be protected can be considered a functional element.

[0020] The present solution is advantageous because, in a complex catheter device, the capture of magnetic abrasion represents an effective option for preventing the entry of magnetic abrasion into the body. This is not easily predictable, since previous catheter devices have often aimed at completely avoiding abrasion through the appropriate choice of materials, coatings and / or geometries, or have had to foresee functional impairments through corresponding parameter limitations (speed limitation, etc.), or have attempted to achieve a return of the particles from the patient through a complex routing of the rinsing solution through multi-lumen catheters, whereby no

[0021] of these options is able to prevent the entry of abrasion of the most distal bearing into the patient.

[0022] Disclosed, among other things, is a separating device for retaining magnetic particles in a fluid, comprising a transport channel in which the fluid can be moved in a flow direction, and a magnetic device. The magnetic device comprises at least one magnet separated from the fluid by a magnetically permeable solid layer. Advantageously, the magnet can be completely insulated from the fluid by the solid layer, in particular, surrounded by the solid layer on all sides.

[0023] The magnetic device of the separating device can, for example, comprise one or more permanent magnets or one or more electromagnets, or a mixture of both. The application of a magnetic field ensures that, as the fluid flows through the transport channel, magnetic particles, such as iron particles, which may be magnetized or unmagnetized, remain attached near the magnet to the inner wall of a flow channel / fluid channel or directly to the solid layer of the magnet. The flow of the fluid through the transport channel or fluid channel is not impeded. Furthermore, the separation of the magnet(s) from the actual fluid ensures that the material of the magnet itself is not damaged, even in the case of highly chemically or physically aggressive fluids, for example when using saline solutions, but also in non-medical applications when using acids or hot liquids.

[0024] To flush the separation device, for example, an electromagnet can be switched off or a permanent magnet can be temporarily removed from the transport channel. This has the advantage that the separation device can be flushed without removing the separation device itself from the transport channel.

[0025] One embodiment may provide that the magnet interacts exclusively with magnetic or magnetizable particles in the fluid in the transport channel.

[0026] The magnet of the separating device is in particular also provided separately from an additional magnet or armature of a pump drive and / or a valve drive, which can be provided adjacent to the separating device, in particular with respect to the preferred flow direction of the fluid downstream of the separating device.

[0027] One embodiment provides that the separating device has a first and a second fluid connection, between which the separating device forms a fluid-tight fluid channel.

[0028] In this case, a fluid channel is formed within the transport channel directly within the frame of the separating device, in which the fluid, for example, a liquid, is moved between a first and second fluid connection, for example, between an inflow channel and an outflow channel. In this case, the fluid channel can form the transport channel or be formed within the transport channel, for example, in the form of a catheter.

[0029] A further embodiment provides that a magnet is arranged in the fluid channel, at least in some areas, in one embodiment also on all sides, around which the fluid can flow, and which is covered by a magnetically permeable solid layer.

[0030] In this case, the magnet is arranged within the fluid channel and can provide the flowing fluid with a maximum interaction surface. It is advantageous to expand the cross-section of the fluid channel accordingly, so that there is enough space for the fluid to flow past the magnet on all sides. The magnet itself can be covered, for example, with a plastic layer or with a sufficiently refined metallization on all sides, or at least on the sides exposed to the fluid. The magnet and its casing should be held within the fluid channel, for example, by struts or another holding device.

[0031] It can advantageously be provided that the magnet is designed as a cylinder or cuboid, the length of which in the longitudinal direction of the fluid channel is greater than its diameter in the transverse direction of the fluid channel and which is arranged in a cylindrical section of the fluid channel.

[0032] In this case, both the cylindrical or square-sectioned section of the fluid channel and the magnet are elongated, so that the fluid flowing past the magnet has sufficient interaction time to attract the corresponding magnetic particles to the magnet and hold them there.

[0033] In addition, it can advantageously be provided that the magnetic field lines within the magnet run transversely, in particular perpendicular to the flow direction of the fluid.

[0034] In this case, a magnetic pole is formed on each side of the magnet where the fluid flows in the longitudinal direction of the fluid channel, holding the corresponding magnetic parts in place. However, the magnetization can also be designed so that the magnetic poles are aligned in the longitudinal direction of the fluid channel. This results in the main interaction surface of the magnet with the magnetic particles in the fluid being located at the two upstream and downstream ends of the magnet.

[0035] The separating device can also be designed such that the magnet has a smaller extension in the flow direction than perpendicular to the flow direction.

[0036] In this case, the magnet can be disk-shaped, with the magnetic disk positioned perpendicular to the fluid flow direction in the fluid channel, potentially creating turbulence in the fluid flowing around the disk. In this case, a certain flow resistance is created by the magnet, but the turbulence of the fluid ensures that all particles in the fluid eventually reach the immediate vicinity of the magnet along their path, where they can be held.

[0037] In the case of an elongated magnet, fixed swirling elements can be provided in the fluid stream in the area of the separating device, which ensure a non-laminar flow and that the particles come close to the magnetic device.

[0038] A further advantageous embodiment provides, for example, an annular body which surrounds the transport channel, wherein the transport channel is designed to receive a catheter with a flow channel and wherein a magnet is arranged in the annular body in a cavity located next to the transport channel.

[0039] In this case, the separating device itself does not come into direct contact with the fluid, but the transport channel is configured to accommodate a catheter with a fluid channel. This has the advantage that the separating device can be installed and removed without interrupting a fluid channel, i.e., for example, without interrupting the fluid flow. For this purpose, it can be provided, for example, that the annular body is formed as a single piece in the circumferential direction. However, it can also be provided that the annular body is interrupted at least once in the circumferential direction and can be folded open, in particular for attachment to a catheter.

[0040] In this case, the application and installation of the separator on a catheter is particularly easy: the separator is simply opened with the ring body and pushed onto the catheter. Removing the separator is also correspondingly simple. However, this design may result in a slightly larger size of the separator compared to a separator with a magnet located in the fluid channel.

[0041] A further embodiment provides that the flow channel has a larger cross-section in the region of the magnetic device than in a region arranged in the direction of the fluid in front of the region of the magnetic device.

[0042] This design slows the fluid flow in the area of the separator due to the enlarged cross-section, regardless of whether the separator comprises a ring body with a magnet surrounding the transport channel or a magnet located in the fluid channel itself, so that the magnetic particles are more likely to be attracted and held by the magnet. Furthermore, this design ensures that the separated particles do not clog the fluid channel or impede the fluid flow. The cross-section of the fluid channel can be reduced directly upstream of the separator, but alternatively or additionally, directly downstream of the separator compared to the area of the separator.The cross-section in the area of the separating device can, for example, be at least twice, in particular at least three times or five times as large as immediately upstream of the separating device, and, for example, also at least two, three, or five times as high as immediately downstream of the separating device in the direction of fluid flow. However, the fluid channel can also be designed such that the magnet transports the particles into a cavity or reservoir so that they do not impede the fluid flow.

[0043] The protective device that can be combined with the catheter is, for example, a protective device for a functional element that is in contact with a flowing fluid, wherein a separating device for retaining particles in the fluid, with at least one magnetic element, in particular a separating device of the type described above, is provided along a flow channel for the fluid, in particular of the catheter, at a distance from the functional element and in particular separated therefrom.

[0044] The separating device can advantageously be provided upstream of the functional element with respect to the prevailing flow direction of the fluid, but the two mentioned elements can also be provided simply one behind the other, in particular spaced apart from each other, for example also structurally separated from each other, for example in the form of two separate components with different housings.

[0045] The functional element can be free of magnetic or magnetically acting elements and, for example, be completely non-magnetic. It can contain one or more ball bearings and / or plain bearings. The functional element can, for example, also have a sealing surface that is to be protected from particles.

[0046] The functional element can also be something else that requires special protection, such as a part of a human or animal body. In most cases, however, the functional element is a bearing, e.g., a plain bearing or a ball bearing, and / or a seal.

[0047] The functional element can also contain magnetic components, such as a drive magnet of a rotor or a translational drive, or a drive magnet of a solenoid valve. The magnetic element of the separating device can be a magnet separate from the magnetic components of the functional element, or it can be a functional surface of a magnetic component that exclusively serves the function of particle separation, whereby other functional surfaces of the magnetic component can perform other functions of the functional element, such as a drive function. In this latter case, the magnetic element of the separating device can be combined with a magnetic component of the functional element, joined to it, combined with it, and in particular also combined in a housing.The functional surface of the separating device can thus capture and bind particles, in particular magnetic and / or magnetizable particles, before they can reach the functional element.

[0048] An additional aspect relates to a functional element which is connected to a separating device, in particular according to the present patent, in particular a valve which has a closure element which can be driven between two end positions, wherein one or two armatures made of a magnetic or magnetizable material or of a material with a particularly low magnetic resistance are integrated into the closure element and wherein a magnet of the separating device is combined with the closure element, in particular is firmly connected thereto, advantageously is integrated therein.

[0049] The invention is shown and explained below using exemplary embodiments in figures of a drawing.

[0050] It shows: FIG. 1 shows a longitudinal section through a separating device with a transport channel designed as a fluid channel in which a magnet is surrounded by a fluid, FIG. 2 shows a catheter device with a rotating shaft and a separating device in a longitudinal section, FIG. 3 shows a cross section through the FIG. 2 shown device, FIG. 4 a magnetic device in which the magnet around which the fluid flows is magnetized transversely to the longitudinal direction of the fluid channel, FIG. 5 a magnet that is magnetized in its longitudinal direction and in the longitudinal direction of the fluid channel, FIG. 6 a valve that is connected to a separating device, FIG. 7 another valve connected to a separating device, FIG. 8 a drive unit for a functional element that can be driven by means of a shaft rotating in a catheter, FIG. 9 a modification of a drive unit according to FIG. 8 , FIG. 10 and FIG. 11 each show further designs of drive devices for shafts rotating in a catheter, and FIG. 12 shows a modification of a drive unit according to FIG. 9 .

[0051] The FIG. 1 shows a longitudinal section through a transport channel 1 which is designed directly as a fluid channel and carries a fluid, for example in the form of a saline solution. The fluid enters the transport channel 1 at an inlet opening 2 and exits it at the outlet opening 3. The flow directions are indicated by arrows 4, 5, 6. At the upstream end of the transport channel 1, a holder 7 for a magnetic device is provided, while at the downstream end, another holder 8 for a magnetic device is provided. The holders 7, 8 can, for example, be designed as support stars with fluid passage openings 9, 10. The cross-section of the flow openings 9, 10 should be large enough that the holders 7, 8 do not represent any significant flow resistance for the fluid.

[0052] The inflow opening 2, as well as the outflow opening 3, can each be connected to a catheter, which can, for example, be pushed onto a connecting piece 11, 12.

[0053] Inside the transport channel, a magnetic device with a permanent magnet 13 is arranged. The magnet is surrounded on all sides by a casing 14 that protects the magnet from the influence of a corrosive fluid. The casing can be implemented, for example, as a plastic casing, a paint coating, or even as a metallization, i.e., a metallic coating made of a precious metal.

[0054] The flow of the fluid through the transport channel 1 will not be strictly laminar, but will exhibit certain turbulences. In any case, the particles 15, 16, which are present as magnetic particles in the fluid circuit, for example, due to abrasion of magnetic parts, will be attracted to certain areas of the magnet. Additional turbulence elements in the transport channel 1 can also ensure that the fluid flow is swirled, thus increasing the probability that particles transported in the fluid will approach the magnet. The term "magnetic particles" refers to all particles that are attracted to a magnet, in particular, but not exclusively, ferromagnetic particles.

[0055] Once the particles have entered the capture area of the magnet, they are held there and kept out of the fluid flow. FIG. 1 The separation device shown can, for example, be used as a disposable separation device and disposed of after use. In this case, the separated metal particles 15, 16 can remain on the magnet 13. It can also be provided that the magnet 13 is designed as an electromagnet or is magnetized from outside the transport channel by a magnetic device. In both of these cases, the magnetization of the magnet 13 can be temporarily removed in order to be able to flush the transport channel and the outer surface of the magnet 13, 14 and to remove the magnetic particles 15, 16. In this case, for example, another catheter can be connected to the connection piece 12, which directs the fluid used for flushing, together with the particles, into a collecting container.

[0056] The magnet 13" can be used as shown in the FIG. 4 shown in more detail, for example by an external magnetization device 17 with an electromagnet part 18 and pole pieces 19, 20, so that its magnetization direction is along the FIG. 4 shown arrows 21, 22 runs transversely to the longitudinal direction of the transport channel (provided that the FIG. 4 The magnet shown is used for a device as shown in the FIG. 1 For rinsing, the electromagnet 18 can then simply be switched off or its action at least partially reversed in order to eliminate the residual magnetization of the magnet 13.

[0057] In the FIG. 5 Another design of a magnet is shown, whereby its outer geometric shape is that of the one in the FIG. 1 corresponds to the magnet shown, the magnetization, indicated by the arrow 23, running in the longitudinal direction of the magnet 13.

[0058] Metallic particles would tend to accumulate at the two axial ends of such a magnet rather than at the long sides as with a magnet used in the FIG. 4 shown magnets magnetized transversely to the longitudinal direction.

[0059] The FIG. 2 shows a catheter device with a catheter 24 in which a rotating metallic shaft 25 is guided. The reference numeral 26 in the FIG. 2 a catheter holder having a transport channel 1'. Reference numeral 27 denotes a housing that surrounds the catheter holder 26 and forms an annular body having a cavity in which a magnet 13' is arranged. Within the housing 27, the shaft 25 exits the catheter 24. The catheter 24 exits the catheter holder 26 or ends at one end of the catheter holder 26. In any case, the fluid in the catheter 24, which flows slowly along the shaft 25 as a rinsing and lubricating fluid, can exit into a fluid channel 28 formed at the end of the catheter 24, which has a significantly larger cross-section than the free cross-section of the catheter 24, which is already reduced by the shaft 25 guided therein. The fluid channel 28 is located upstream of a mechanical bearing 29, which can be designed as a plain bearing, and in the direct sphere of influence of the magnet 13'.The magnet 13' is designed as a permanent magnet, but can also be designed as an electromagnet.

[0060] In the area of the fluid channel 28, the magnetic particles 30 collect on the wall of the channel facing the magnet 13'. In this way, the magnetic particles are retained from the fluid and do not reach the bearing 29.

[0061] The further extension of the shaft 25 is not shown, but further downstream of the connecting coupling 31, further mechanically functioning parts, such as pumps or milling cutters driven by the shaft, may be provided, which must be protected from the influence of the magnetic particles. In addition to the catheter holder 26, the housing 27 also houses a flushing device with connecting nozzles 32, 33 for a flushing fluid to flush the catheter 24.

[0062] The magnet 13' can be removed from the housing 27 to remove the trapped magnetic particles 30, allowing the magnetic particles to be flushed away. This should be done outside of the operating hours of the shaft and the corresponding bearings and functional elements to protect them. If the magnet 13' is an electromagnet, it can simply be temporarily switched off for flushing.

[0063] In the FIG. 3 is a cross-section through the catheter arrangement from the FIG. 2 shown, with the housing 27, the transport channel 28 in the area behind the end of the catheter 24 and the magnet 13' located in a cavity of the housing 27.

[0064] FIG. 6 shows a solenoid valve with a transport channel 1", through which a fluid flows between an inlet opening 2' and an outlet opening 3'. A closure body 50 can be driven within the transport channel 1" between a first closure position and a second closure position, wherein in the first closure position a first closure surface 51 closes a valve opening 51a, while in the second closure position a closure surface 52 closes a valve opening 52a.

[0065] Two armature bodies 53, 54 are integrated into the closure body 50, which can be driven by the magnetic field of two valve drive coils 55, 56. The magnet 13" of the separating device is arranged axially between the armature bodies 53, 54 and aligned with them. The armature bodies, including the magnet body 13", are provided with a common solid coating.

[0066] Retaining springs 57, 58 hold the closure body in a central position, in which the valve is open, in the absence of energization of the valve drive coils. Two plain bearings 59, 60 are provided at the ends of the valve housing to guide the closure body 50.

[0067] FIG. 7 shows a valve with an inlet opening 2", an outlet opening 3", and a closure body 50'. The closure body 50' can be driven within the transport channel 1' between a first closure position and a second closure position, wherein in the first closure position a first closure surface 51' closes a valve opening 51a', while in the second closure position a closure surface 52' closes a valve opening 52a'. The closure body 50' is mounted in the housing of the valve by means of an elastic, permeable disc 61 and is held in an open central position. The disc 61 carries separating magnets 13'', 13"", which are connected to valve drive armatures 62, 63 in the closure body 50' and are enclosed together with these by a protective layer.

[0068] The valve drive armatures 62, 63 are driven in the field of the coils 64, 65. Particles can attach to the separating magnets on the protective layer in the transport channel and are held there.

[0069] The FIG. 8 shows a drive device with a rotatably driven drive armature 66, which drives a rotating shaft 67 in a catheter 68. Within the catheter 68, an inflow channel 69 is arranged radially outward and a return flow channel 70 is arranged radially inward, concentric with each other and with the outer sheath of the catheter. The inflow channel 69 and the return flow channel 70 are separated from each other by a tubular partition 71.

[0070] A volume-controlled peristaltic pump 72 pumps a rinsing fluid from a reservoir 73 through a cannula 74 and a valve 75. Two magnets 76 and 77 drive the valve and are controlled by a pressure switch 78 with the aim of maintaining a constant pressure in the inflow channel 69. For this purpose, the fluid is directed through the valve 75 and through the housing of the drive armature 66, the transport channel 79, and through the separating device 80, where particles are actively filtered out of the fluid. The separating device 80 can be constructed like the one shown in the FIG. 1 shown separating device. From there, the fluid flows into the catheter 68 through the inflow channel 69 radially outward and the return flow channel 70 radially inward, and from there to a peristaltic pump 81, which sucks in the fluid and directs it into the reservoir 82. However, the peristaltic pump 81 can also be used for backflushing and, for this purpose, can be operated in such a way that it conveys the fluid to the return flow channel 70 and from there via the inflow channel 69, through the separating device back to the valve 75 into the reservoir 73, for example to remove the trapped particles from the separating device.

[0071] The FIG. 9 shows a structure similar to that of FIG. 8 , wherein in addition to the valve 75 in front of the drive armature 66 and behind the hose pump 72, a second valve 75' is arranged between the return flow channel 70 and the return flow pump 80. While FIG.8 is used in flushing systems in which system components do not create unwanted negative pressure in the return line, it is possible FIG.9 Also suitable for flushing systems in which an unwanted negative pressure develops in the return flow (e.g., due to the winding direction of a flexible shaft). This negative pressure is detected by the sensor, which then ensures, by closing the valve 75' downwards, that no medium from container 82 enters the flushing circuit via the pump 81. The separating device is thus arranged between two valves and also between two fluid conveying devices, of which at least one, in particular both, can be switched with respect to the conveying direction of the fluid in order to reverse the flow direction.

[0072] When setting up according to FIG. 10 is compared to the structure in FIG. 8 merely a peristaltic pump 72 is replaced by a reservoir 83, which allows gravity flushing, as the fluid flows by gravity through the valve 75 and further to the catheter 68. The rotating shaft 84 within the catheter 68 has a coiled outer structure due to its stranded construction based on stranded wires, which gives it a pumping effect in the direction away from the drive armature 66 even when rotating. On the right side of the FIG. 10 To the right of the dashed line 85, another variant for the flow of fluid to the catheter 68 is shown, with a volume-controlled peristaltic pump 72 and a reservoir 73. The peristaltic pump conveys the fluid to the interior of the catheter, which, for example, leads into the body of a patient and ends there at a heart pump 85 with a rotor 85a. The heart pump can, for example, be radially compressible or, overall, particularly susceptible to particles getting into it. From there, the fluid then flows back. A separating device 80 can be provided in each case in the flow direction upstream of the catheter 68 between the catheter and the conveying device 73, 83, in particular in any case upstream of the heart pump 85.

[0073] The FIG. 11 shows a constellation similar to that of FIG. 9 , wherein instead of the peristaltic pump 72, a gravity feed 83 is provided, wherein the fluid flows from there via the valve into the catheter 68 and from there initially through the inflow channel 69 radially outwards into the return flow channel 70 radially inwards and from there to a peristaltic pump 81, which sucks in the fluid and directs it into the reservoir 82. Between the return flow channel 70 and the peristaltic pump 81, the fluid first passes the separating device 80, which is arranged between the return flow channel and the housing of the drive armature 66. The fluid then flows past the drive armature 66 to the peristaltic pump 81. The bearing of the drive armature can be relatively insensitive, so that the direction of flow of the fluid is of secondary importance there. It is particularly important that the housing of the drive armature is supplied with the fluid in order to ensure good lubrication.The selected arrangement also ensures that magnetic abrasion particles from the rotating shaft 84 cannot damage the bearings of the drive armature in this case.

[0074] The FIG. 12 shows a structure similar to the FIG. 9 , wherein a further separating device 80' ensures that the function of the sealing surfaces of the valve 75' is not impaired by adhering particles.

[0075] The invention allows, particularly in medical applications, but also in other applications, to retain magnetic particles from a fluid stream by means of magnetic devices, wherein the magnets of the magnetic devices are protected from corrosive effects of the fluid.

[0076] The invention is defined by the claims.

[0077] The catheter device according to the invention can be combined with all separating devices shown here, for example, separating devices according to the description of the figures. For this purpose, it is also possible to provide not just one, but also several separating devices per catheter device.

[0078] For example, the following applies to the separating devices: The separating device can be designed as a separating device for retaining magnetic particles located in a fluid, with a transport channel in which the fluid can be moved in a flow direction, and with a magnetic device, wherein the magnetic device has at least one magnet which is separated from the fluid by a magnetically permeable solid layer.

[0079] In this separation device, the magnet may interact exclusively with magnetic or magnetizable particles in the fluid in the transport channel.

[0080] Alternatively or additionally, the separating device may have a first and a second fluid connection, between which the separating device forms a fluid-tight fluid channel.

[0081] In the separating device, a magnet surrounded by a magnetically permeable solid layer can be arranged in the fluid channel around which the fluid flows on all sides.

[0082] In the separating device in which a magnet is arranged in the fluid channel around which the fluid can flow on all sides and which is covered with a magnetically permeable solid layer, the magnet can be designed as a cylinder or cuboid whose length in the longitudinal direction of the fluid channel is greater than its diameter and which is arranged in a cylindrical section of the fluid channel.

[0083] In a magnet designed in this way, the magnetic field lines can optionally run transversely within the magnet, in particular perpendicular to the flow direction of the fluid.

[0084] In the separating device in which a magnet is arranged in the fluid channel around which the fluid can flow on all sides and which is covered with a magnetically permeable solid layer, the magnet can have a smaller extension in the flow direction than perpendicular to the flow direction.

[0085] The separating device can comprise an annular body surrounding the transport channel, wherein the transport channel is configured to receive a catheter having a flow channel and wherein a magnet is arranged in the annular body in a cavity located adjacent to the transport channel.

[0086] The ring body can be formed in one piece in the circumferential direction.

[0087] Alternatively, the ring body can be interrupted at least once in the circumferential direction and can be opened up, in particular for attachment to a catheter.

[0088] In the separating device, the flow channel in the region of the magnetic device can have a larger cross-section than in a region arranged in the flow direction of the fluid upstream of the region of the magnetic device.

[0089] The invention is defined by the claims. The following examples disclose aspects of catheter devices, catheter systems, and protective devices, respectively, which are helpful for understanding the invention defined by the claims: A catheter device can be designed as a catheter device with a catheter in which a rotating shaft consisting at least partially of a magnetic material is arranged, and with a separating device which contains an annular body surrounding the rotating shaft and having a cavity containing a magnetic body, wherein the magnetic body is arranged downstream of a point at which the shaft exits the surrounding catheter with respect to the direction of flow of the fluid through the catheter.

[0090] A protective device can be designed as a protective device for a functional element that is in communication with a flowing fluid, wherein a separating device for retaining particles present in the fluid, comprising at least one magnetic element, is provided along a flow channel for the fluid, in particular a catheter, spaced from and in particular separated from the functional element. This can, in particular, be a separating device from one of the above examples.

[0091] A catheter system may include a separating device that includes the features from one of the above examples and / or it may comprise the aforementioned protective device, wherein at least one electrical element for controlling a functional element and / or for magnetic control is separable from the rest of the catheter system.

[0092] Further examples of a catheter device are described below: The catheter device can be designed as a catheter device with a catheter 24 in which a rotating shaft 25 consisting at least partially of a magnetic material is arranged, and with a separating device which contains an annular body 27 surrounding the rotating shaft and having a cavity containing a magnetic body 13', wherein the magnetic body is arranged downstream of a point at which the shaft 25 emerges from the catheter 24 surrounding it with respect to the flow direction of the fluid through the catheter.

[0093] The catheter device can be designed as a catheter device for retaining magnetic particles 15, 16 located in a fluid, with a transport channel 1, 1', in which the fluid can be moved in a flow direction 4, 5, 6, and with a magnet device 13, 13', 13", 14, 18, 19, 20, wherein the magnet device has at least one magnet 13, 13', 13" which is separated from the fluid by a magnetically permeable solid layer 14.

[0094] In the catheter device for retaining magnetic particles in a fluid, the magnet can, for example, interact exclusively with magnetic or magnetizable particles in the fluid in the transport channel.

[0095] The catheter device can have a first and a second fluid connection 11, 12, between which the separating device forms a fluid-tight fluid channel.

[0096] In the catheter device, it can be provided that a magnet 13, 13" is arranged in the fluid channel, around which the fluid can flow and which is covered by a magnetically permeable solid layer 14.

[0097] This magnet 13, 13" may be designed as a cylinder or cuboid, the length of which in the longitudinal direction of the fluid channel is greater than its diameter, and which is arranged in a cylindrical section of the fluid channel.

[0098] Then, the magnetic field lines within the magnet 13, 13" can continue to run transversely, in particular perpendicularly to the flow direction of the fluid.

[0099] The mentioned magnet 13, 13', 13" may have a smaller extension in the flow direction than perpendicular to the flow direction.

[0100] The catheter device can have an annular body 27 which surrounds the transport channel 1', wherein the transport channel is designed to receive a catheter 24 with a flow channel and wherein a magnet 13' is arranged in the annular body 27 in a cavity located next to the transport channel.

[0101] This annular body 27 can be formed in one piece in the circumferential direction.

[0102] Alternatively, the annular body 27 can be interrupted at least once in the circumferential direction and can be opened up, in particular for attachment to a catheter 24.

[0103] In the catheter device, the flow channel in the region of the magnetic device 13, 13', 13", 14, 18, 19, 20 can have a larger cross-section than in a region arranged in the flow direction of the fluid upstream of the region of the magnetic device.

[0104] The catheter device can be provided with at least one valve for controlling a fluid flow through the catheter, the valve comprising: a valve control chamber into which an inflow channel with an inflow opening and an outflow channel with an outflow opening open, and a closure element which can be moved in a controlled manner in the valve control chamber and which keeps the outflow opening open in at least one first position and a connecting channel between the inflow opening and the outflow opening open in at least one third position, a valve drive being provided which selectively moves the closure element at least into the first, second or third position.

[0105] In the catheter device, it can be provided that the transport channel 1, 1' has a reservoir for the intermediate storage of particles.

[0106] This reservoir can be magnetically influenced in such a way that metallic particles remain in the reservoir even when the transport channel 1, 1' is flowing through.

[0107] Alternatively or additionally, the reservoir may have two ends, both of which are fluidically connected to the transport channel 1, 1'.

[0108] The reservoir may alternatively or additionally be designed as a spatially limited cross-sectional enlargement of the transport channel 1, 1'.

[0109] A protective device can be designed as a protective device for a functional element which is in communication with a flowing fluid, wherein a separating device for retaining particles in the fluid with at least one magnetic element is provided along a flow channel for the fluid, in particular a catheter, spaced from the functional element and in particular separated therefrom.

[0110] In the protective device, it can be provided that the functional element is a seal and / or a bearing, in particular a ball or plain bearing.

Claims

1. A catheter device for retaining magnetic particles (15, 16) located in a fluid configured as a flushing liquid, with a transport channel (1, 1') in which the fluid may be moved in a flow direction (4, 5, 6), and with a magnet device (13, 13', 13", 14, 18, 19, 20), wherein the magnet device (13, 13', 13", 14, 18, 19, 20) has at least one magnet (13, 13', 13") which is separated from the fluid by a magnetically permeable solid layer (14), and with a shaft (25, 84) rotating in a catheter (24, 68) belonging to the catheter device, and with a heart pump (85) with a rotor (85a), wherein the catheter (24, 68) is configured such that the flushing liquid flows along the shaft (25, 84) as a flushing and lubricating liquid.

2. The catheter device according to claim 1, characterised in that in the transport channel configured as a fluid channel there is disposed the magnet (13, 13") which is surrounded by a magnetically permeable solid layer (14) and around which the fluid may flow.

3. The catheter device according to claim 2, characterised in that the magnet (13, 13") is configured as a cylinder or cuboid of which the length in the longitudinal direction of the fluid channel is greater than its diameter, and which is arranged in a cylindrical portion of the fluid channel.

4. The catheter device according to claim 3, characterised in that the magnetic field lines within the magnet (13, 13") run transversely, in particular perpendicularly to the flow direction of the fluid.

5. The catheter device according to claim 2, characterised in that the magnet (13, 13', 13") has a smaller extent in the flow direction than perpendicular to the flow direction.

6. The catheter device according to any one of the preceding claims, characterised by a ring body (27) surrounding the transport channel (1'), wherein the transport channel is set up to accommodate a catheter (24) with a flow channel, and wherein a magnet (13') is arranged in the ring body (27) in a cavity located next to the transport channel.

7. The catheter device according to claim 6, characterised in that then ring body (27) is formed in one piece in the circumferential direction.

8. The catheter device according to claim 6, characterised in that the ring body (27) is interrupted at least once in the circumferential direction and in particular may be opened to be attached to a catheter (24).

9. The catheter device according to any one of claims 1 to 8, characterised in that the fluid channel in the region of the magnet device (13, 13', 13", 14, 18, 19, 20) has a larger cross-section than in a region arranged in the direction of flow of the fluid upstream of the region of the magnet device.

10. The catheter device according to one of claims 1 to 9, characterised in that it has at least one valve for controlling fluid flow through the catheter (24, 68), wherein the valve comprises: a valve control chamber into which an inflow channel with an inflow opening (2', 2") and an outflow channel with an outflow opening (3', 3") open, and a closure element (50, 50') movable in a controlled manner in the valve control chamber, which closure element in at least a first position closes the outflow opening (3', 3"), in at least one second position closes the inflow opening (2', 2"), and in at least one third position keeps a connecting channel between the inflow opening (2', 2") and the outflow opening (3', 3") open, wherein a valve drive is provided which selectively moves the closure element (50, 50') into at least the first, second or third position.

11. The catheter device according to any one of the preceding claims, characterised in that the transport channel (1, 1') has a reservoir (73, 82) for storing particles temporarily.

12. The catheter device according to claim 11, characterised in that the reservoir is magnetically influenced such that metal particles remain in the reservoir even when a flow passes through the transport channel (1, 1').

13. The catheter device according to any one of claims 11 or 12, characterised in that the reservoir has two ends, wherein both are fluidically connected to the transport channel (1, 1'), and / or in that the reservoir is configured as a spatially delimited cross-sectional enlargement of the transport channel (1, 1').

14. The catheter device according to any one of the preceding claims, characterized in that the shaft (25, 67) consists at least partially of a magnetic material, and wherein the catheter device comprises a separating device (80) which contains a ring body surrounding the shaft (25, 67) with a cavity containing a magnet body, wherein the magnet body, with respect to the direction of flow of the fluid through the catheter (24, 68), is arranged downstream of a point at which the shaft (25, 67) emerges from the catheter (24, 68) surrounding it.

15. The catheter device according to any one of claims 1 to 13, characterised by a protective device for a functional element of the catheter, wherein the functional element is in communication with a flowing fluid, and wherein a separating device for retaining particles located in the fluid is provided along the catheter, spaced apart from the functional element and, in particular, separated from it, and comprises at least one magnet element.